Custom Item Icons

[Chicago119]

I'm fairly new to modding this game. I'm not looking to make a full spritesheet for an entity out of a 3d model, but I am looking for a guide on making a basic PNG spritesheet in a compatible format/dimensions for a new intermediate item. I can see the spritesheets here for the vanilla intermediates but it's different from something like Rimworld which I have worked on before and isn't a rigidly defined spritesheet per se.

Note that at the moment I'm just trying to reposition some ore chunks from individual ore sprites. I'm not trying to model a whole new type of rock, there's really no point for making a bespoke spodamene ore that is just going to look like differently colored stone anyway.

[Osmo]

The base game icons have mipmaps (smaller versions of the image). These are only worth making when you want to modify them, as they will be auto generated by the game, and can be ignored most of the time. So all you need is just a square image, ideally 64 pixels in size.